Resol beads, methods of making them, and methods of using them

Abstract

Resol beads are disclosed prepared by reaction of a phenol with an aldehyde, with a base as catalyst, in the presence of a colloidal stabilizer, and optionally a surfactant. The resol beads have a variety of uses, and may be thermally treated and carbonized to obtain activated carbon beads.

1 . A continuous process for producing resol beads, the process comprising:
 a) adding and reacting reactants comprising a phenol and with an aldehyde, in the presence of a base as catalyst, in an agitated aqueous medium that comprises a colloidal stabilizer, and optionally a surfactant, for a period of time and at a temperature sufficient to produce an aqueous dispersion of resol beads;   b) recovering water-insoluble resol beads above a minimum particle size from the aqueous dispersion; and   c) retaining or recycling beads below the minimum particle size in or to the aqueous dispersion of resol beads, to serve as seed particles during the process in which reactants are continuously added.   
     
     
         2 . The process according to  claim 1 , wherein the minimum particle size is from about 50 μm to about 1,500 μm. 
     
     
         3 . The process according to  claim 1 , wherein the minimum particle size is from 100 μm to 750 μm. 
     
     
         4 . The process according to  claim 1 , wherein the minimum particle size is from 250 μm to 500 μm. 
     
     
         5 . The process according to  claim 1 , wherein the phenol comprises monohydroxybenzene. 
     
     
         6 . The process according to  claim 1 , wherein the aldehyde comprises formaldehyde. 
     
     
         7 . The process according to  claim 1 , wherein the base comprises one or more of ammonia or ammonium hydroxide. 
     
     
         8 . The process according to  claim 1 , wherein the molar ratio of the aldehyde to the phenol is from about 1.1:1 to about 3:1. 
     
     
         9 . The process according to  claim 1 , wherein the colloidal stabilizer comprises a carboxymethyl cellulose salt. 
     
     
         10 . The process according to  claim 9 , wherein the carboxymethyl cellulose salt has a degree of substitution from about 0.6 to about 1.1 and a weight average molecular weight from about 100,000 to about 400,000. 
     
     
         11 . The process according to  claim 1 , wherein the temperature is from about 70° C. to about 98° C. 
     
     
         12 . The process according to  claim 1 , wherein the temperature is from 75° C. to 90° C. 
     
     
         13 . The process according to  claim 1 , wherein the water-insoluble resol beads recovered have a median sphericity value from about 0.90 to 1.0. 
     
     
         14 . The process according to  claim 1 , wherein the surfactant is present and comprises one or more of: sodium dodecyl sulfate or sodium dodecyl benzene sulfonate. 
     
     
         15 . The process according to  claim 1 , wherein the base comprises one or more of: ammonia or hexamethylenetetramine. 
     
     
         16 . The process according to  claim 1 , wherein methanol is present in the aldehyde provided to the reaction mixture in an amount of no more than about 2 wt. %, based on the total weight of the aldehyde. 
     
     
         17 . The process according to  claim 1 , wherein the agitated aqueous medium is agitated by one or more of: a pitched blade impeller; a high efficiency impeller; a turbine; an anchor; a spiral agitator; a rotating agitator; a flow induced by circulation; or flowing the aqueous medium past a stationary mixing device. 
     
     
         18 . The process according to  claim 1 , wherein the beads above a minimum particle size have a median sphericity value from about 0.90 to 1.0, and are recovered from the aqueous dispersion using a physical aperture. 
     
     
         19 . The process according to  claim 18 , wherein the physical aperture comprises one or more of: a screen, a slit, or a hole in a plate. 
     
     
         20 . The process according to  claim 1 , wherein the beads above a minimum particle size are recovered from the aqueous dispersion using a centrifuge. 
     
     
         21 . The process according to  claim 1 , wherein the resol beads recovered comprise from about 0.5% nitrogen to about 3% nitrogen, based on elemental analysis. 
     
     
         22 . The process according to  claim 1 , wherein the resol beads recovered comprise from 0.8% nitrogen to 2.6%, based on elemental analysis. 
     
     
         23 . The process according to  claim 1 , wherein the resol beads retained or recycled are soluble in methanol in an amount up to 20 wt. %. 
     
     
         24 . The process according to  claim 1 , wherein the resol beads retained or recycled have a T g  from about 30° C. to about 120° C., as measured by DSC. 
     
     
         25 . The process according to  claim 1 , wherein the resol beads retained or recycled have a T g  from 30° C. to 68° C., as measured by DSC. 
     
     
         26 . The process according to  claim 1 , wherein the resol beads recovered have an acetone solubility of no more than about 5%. 
     
     
         27 . The process according to  claim 1 , wherein the resol beads recovered have an acetone solubility of no more than 15%. 
     
     
         28 . The process according to  claim 1 , wherein the resol beads recovered have an acetone solubility of no more than 26% 
     
     
         29 . The process according to  claim 1 , wherein the resol beads recovered have an acetone solubility of no more than 30%. 
     
     
         30 . The process according to  claim 1 , wherein the resol beads recovered have a density from about 0.3 g/mL to about 1.3 g/mL. 
     
     
         31 - 88 . (canceled)